Belgrade sewer lagoon

An aerial photo shows the Belgrade sewage lagoons located on airport land east of town. The city is poised to build a new sewage treatment plant this summer.

The Belgrade City Council approved a plan Monday for allocating remaining sewer plant capacity for development projects that might be built before the city’s wastewater treatment system expansion is complete.

Belgrade’s sewer system is currently operating under a variance from the state Department of Environmental Quality, or DEQ, that allows the city to treat up to 1.25 million gallons of wastewater per day. The system was designed to handle only 903,000 gallons per day, and the DEQ permit was issued on the condition that the city remain within its discharge permit loading requirements.

Meanwhile, development is occurring at a rapid pace in Belgrade. The city placed a moratorium on permits for building projects in newly annexed areas until there is additional wastewater treatment capacity. However, staff members anticipate there may be more demand than capacity allows for building permits in areas where the moratorium doesn’t apply.

Bids for expansion of the sewer treatment plant are being solicited now, and work on the project is set to begin this summer, with completion sometime in 2021. In the meantime, as City Engineer Keith Waring told the council, the existing plant has 1.213 million gallons per day in remaining capacity – enough to accommodate 181 new units. The city expects there could be requests for as many as 2,973 new units prior to completion of the plant expansion, with 80 percent of them in new subdivisions and 20 percent in “infill” areas.

In order to allocate the scarce resource fairly, Waring and other city staff members recommended that 20 percent, or 32 units, of the remaining capacity be reserved for infill projects, and 80 percent (129 units) be designated for units in new developments. The council approved the recommendation unanimously.

Waring said it’s possible the city may be able to permit more than 181 new units because the DEQ has indicated it is willing to recalculate Belgrade’s existing plant capacity before the expansion is finished. The agency typically calculates sewer capacity loads when subdivisions are approved – that is, before units are constructed and begin contributing to the load on treatment facilities.

Incorporated into DEQ’s current calculations for Belgrade are the large Prescott Ranch subdivision and the Yellowstone Airport Plaza, neither of which are fully developed. If DEQ revises its figures based on the actual number of units currently adding to the treatment plant’s load, the amount of plant capacity available would increase substantially, Waring said.

In other business, the council:

  Denied a developer’s request for a variance from city specifications that require extending water and sewer lines to property boundaries. The developer of a lot in the Belgrade North Business Park, located at Glider and Jackrabbit lanes, wished to postpone the utility extension until a later date.

  Approved proposed changes to the layout of the Ryen Glen Park. The new plan includes slight relocation of a park trail and the elimination of berms that were included in the original development plan approved by the council.